Bicycle frame



FIG. 1 is a perspective view of a bicycle frame showing our new design;

FIG. 2 is a left side view, the broken lines are shown for illustrative purposes only and form no part of the claimed design;

FIG. 3 is a right side view of the bicycle frame;

FIG. 4 is a left side view of the bicycle frame;

FIG. 5 is a front view of the bicycle frame;

FIG. 6 is a back view of the bicycle frame;

FIG. 7 is a bottom view of the bicycle frame; and,

FIG. 8 is a top view of the bicycle frame. 

The ornamental design for a bicycle frame, as shown and described. 